Assessment focuses: AF2, AF3, AF4, AF5
Context
Pupils chose various materials that might be used in sailing jackets and investigated their insulating properties.
Pupil's work
Sailing JacketMy Aim:I am going to investigate which material is most suitable for the insulating layer of a jacket. I think that bubble wrap will be the best insulating material because the bubble wrap has bubbles full of air, and air is a good insulator.My input variable is the material. My outcome variable is the temperature change.To make my experiment fair, I will start the experiment at the same time, each copper can will have same amount of hot water in, all cans have same thickness of material.
Pupil F was offered a choice of thermometers reading to +/-1°C or temperature probes reading to +/-0.1°C. He chose the temperature probes because he said it would be ‘easier to notice small changes’.
Method:Set up all equipment as shown on the graph, make sure all copper cans have same thickness of material.Fill up the copper cans with hot water. CAUTION! be careful - don't over flow, and fill up all cans to the same point.Start experiment, at a section time selected take measurements of how hot the water is.Results of trial experimentBubble wrap turned out to be the best insulator in out trial (practice) experiment.ConclusionI can see a pattern in my results which is Cotton wool and bubble wrap are both good insulators, cotton wool is better by a bit - as shown on graph.
From the analysis of my results concluded that cotton wool was the best insulator and cotton fabric was the worst insulator. This is because in cotton wool there are lots of air particles trapped inside the wool - air is a good insulator. Cotton fabric is the worst insulator because in cotton fabric there is no air and without air it is useless, this is why cotton wool is the best insulator.All results fit the results pattern because there is a good curve shape of results (as shown on graph) and no results are out of the pattern.There are several improvements I could make. The first one is: spend more time doing the experiment - 5 hours was just enough time so next time I would give it a few more hours.The second one is: find a way of being more exact with the thickness of the material going around the copper cans, and finally I could use more materials to test.
After carrying out preliminary work, Pupil F decided to record temperature changes in six different materials over five hours using the data-logger. He decided that repeat sets of measurements were not necessary, given the quality and amount of data gathered.
The graph describes amount of time taken by a number of materials which cool down to a certain temperature. The materials can be used as insulators on a sailing jacket. In the graph, the red curve depicts polystyrene foam, blue curve depicts bubble wrap, green curve depicts 85% cotton and 15% polyester fabric, Purple curve depicts cotton wool, brown curve depicts Cotton fabric and orange curve depicts aluminum foil.
He recognised the risk posed by the hot water when filling the containers and suggested that care should be taken to make sure they did not overflow. During the practical activity he worked safely, taking account of the dangers he had identified.
